Effect of Fibrillization pH on Gelation Viscoelasticity and Properties of Biofabricated Dense Collagen Matrices via Gel Aspiration-Ejection.

Reconstituted hydrogels based on the self-assembly of acid-solubilized collagen molecules have been extensively used as in vitro models and precursors in biofabrication processes. This study investigated the effect of fibrillization pH-ranging from 4 to 11-on real-time rheological property changes during the gelation of collagen hydrogels and its interplay with the properties of subsequently biofabricated dense collagen matrices generated via automated gel aspiration-ejection (GAE). A contactless, nondestructive technique was used to characterize the temporal progression in shear storage modulus (G', or stiffness) during collagen gelation.

In Vitro Evaluation of Real-Time Viscoelastic and Coagulation Properties of Various Classes of Topical Hemostatic Agents Using a Novel Contactless Nondestructive Technology.

Hemorrhaging is the main cause of death among combat and civilian injuries and has significant clinical and economic consequences. Despite their vital roles in bleeding management, an optimal topical hemostatic agent (HA) has yet to be developed for a particular scenario. This is partly due to a lack of an overarching quantitative testing technology to characterize the various classes of HAs in vitro.

Aluminum-free glass ionomer cements containing 45S5 Bioglass and its bioglass-ceramic.

Although the incorporation of bioactive glasses into glass ionomer cements (GICs) has led to promising results, using a bioactive glass as the only solid component of GICs has never been investigated. In this study, we developed an Al-free GIC with standard compressive strength using various combinations of 45S5 Bioglass and its glass-ceramic as the solid component. The glass-ceramic particles with 74% crystallinity were used for this purpose as they can best act as both remineralizing and reinforcing agents.

A nondestructive contactless technique to assess the viscoelasticity of blood clots in real-time.

There is a need for reliable and quantitative real-time assessment of blood properties to study and treat a broad spectrum of disorders and cardiovascular diseases as well as to test the efficacy of hemostatic agents. In this study, the real-time changes in viscoelastic/rheological properties of bovine whole blood during coagulation induced by different concentrations of calcium chloride (CaCl; 15, 25, 35 and 45 mM) was investigated. For this purpose, a novel, contactless technique was used to accurately measure the clotting characteristics under controlled and sterile conditions.

Poly(d,l-Lactic acid) Composite Foams Containing Phosphate Glass Particles Produced via Solid-State Foaming Using CO for Bone Tissue Engineering Applications.

This study reports on the production and characterization of highly porous (up to 91%) composite foams for potential bone tissue engineering (BTE) applications. A calcium phosphate-based glass particulate (PGP) filler of the formulation 50PO-40CaO-10TiO mol.%, was incorporated into biodegradable poly(d,l-lactic acid) (PDLLA) at 5, 10, 20, and 30 vol.

Glass ionomer cements with enhanced mechanical and remineralizing properties containing 45S5 bioglass-ceramic particles.

The clinical applications of glass ionomer cements (GICs) are limited by their relatively poor mechanical properties and insufficient remineralizing capacity. In this study, we developed hybrid GICs with improved mechanical and remineralizing properties via incorporation of an optimum amount (5 wt%) of 45S5 bioglass-ceramic particles. Also, we found that bioglass-ceramic particles with 74% crystallinity best act as both remineralizing and reinforcing agents.

Ultraporous Membranes Electrospun from Nonsolvent-Induced Phase-Separated Ternary Systems.

Electrospinning of nonsolvent-induced phase-separated ternary (NIPST) systems has gained a lot of interest due to its potential to produce (nano)fibers, which are superficially and internally porous with nanoscale surface roughness. Membranes produced from such systems are expected to have a high specific surface area (SSA; e.g.

Morphological examination of highly porous polylactic acid/Bioglass scaffolds produced via nonsolvent induced phase separation.

In this study, we produce highly porous (up to ∼91%) composite scaffolds of polylactic acid (PLA) containing 2 wt % sol-gel-derived 45S5 Bioglass particles via nonsolvent induced phase separation at -23°C with no sacrificial phases involved. Before the incorporation of the bioglass with PLA, the particles are surface modified with a silane coupling agent which effectively diminishes agglomeration between them leading to a better dispersion of bioactive particles throughout the scaffold. Interestingly, the incorporation route (via solvent dichloromethane or nonsolvent hexane) of the surface modified particles in the foaming process has the greatest impact on porosity, crystallinity, and morphology of the scaffolds.

Synthesis of 45S5 Bioglass® via a straightforward organic, nitrate-free sol-gel process.

More than four decades after the discovery of 45S5 Bioglass® as the first bioactive material, this composition is still one of the most promising materials in the tissue engineering field. Sol-gel-derived bioactive glasses generally possess improved properties over other bioactive glasses, because of their highly porous microstructure and unique surface chemistry which accelerate hydroxyapatite formation. In the current study, a new combination of precursors with lactic acid as the hydrolysis catalyst have been employed to design an organic, nitrate-free sol-gel procedure for synthesizing of 45S5 Bioglass®.